Fluid vaporization tester with hot air purge and method

ABSTRACT

A visual fluid vaporization indicator in which a sample of the test fluid is placed in a boiler, heated to cause a percolating action until a fluid column surges through the visual indicator tube at the vaporization temperature of the fluid, this temperature being measured and considered to be the boiling point of the fluid sample. After the test is completed, a drain valve is opened to drain the fluid sample from the boiler, and a cooling fan is energized to blow air to cool the boiler, hot air having passed over the boiler being directed through the boiler and the visual indicator tube and out the drain valve to purge the system of the remains of the fluid which was tested, as well as cooling the boiler, prior to inserting another fluid sample.

United States Patent Markey [54] FLUID VAPORIZATION TESTER WITH HOT AIR PURGE AND METHOD [72] Inventor: Francis J. Markey, Lewisburg, Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Jan. 29, 1971 [21] Appl. No.: 110,853

[52] U.S.Cl. ..73/17A [51] Int. Cl. ..G0ln 25/02 [58] Field of Search ..73/15, 17

[56] References Cited UNITED STATES PATENTS 2,971,370 2/1961 Jacobs et a]. ..73/36 3,521,480 7/1970 Cropper et a1 ..73/36 1,747,742 2/1930 Stein ..73/l7 OTHER PUBLICATIONS Topham, Multistream Distillation Monitors in Control Engineering, Vol. 1 1, No. 4, April 1964.

[4511 Oct. 17,1972

Primary Examiner-Richard C. Queisser Assistant Examiner-Herbert Goldstein Attorney-W. E. Finken and D. D. McGraw [57] ABSTRACT A visual fluid vaporization indicator in which a sample of the test fluid is placed in a boiler, heated to cause a percolating action until a fluid column surges through the visual indicator tube at the vaporization tempera .ture of the fluid, this temperature being measured and considered to be the boiling point of the fluid sample. After the test is completed, a drain valve is opened to drain the fluid sample from the boiler, and a cooling fan is energized to blow air to cool the boiler, hot air having passed over the boiler being directed through the boiler and the visual indicator tube and out the drain valve to purge the system of the remains of the fluid which was tested, as well as cooling the boiler, prior to inserting another fluid sample.

3 Claims, 2 Drawing Figures U. a I is! y I. a i ii e #4 "ii $2 K e: ii #5 DRAIN PAN FANON EATON 7;

P'A'TENTEDum 11 1972 DRAIN PAN 5 FAN ON 2;;

OFF

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ATTORNEY FLUID VAPORIZATION TESTER WITH HOT AIR PURGE AND METHOD The invention relates to a fluid vaporization testing mechanism and a method of testing and preparing the mechanism for further testing, and more particularly to mechanism and method in which a sample of fluid is heated, percolated to determine the fluid vaporization temperature, the mechanism then being purged by hot air, as well as being cooled by air to prepare the mechanism for the next test sample.

The invention is an improvement over that disclosed and claimed in US. Pat. application Ser. No. 838,514 entitled Fluid Vaporization Tester and Method and filed July 2, 1969 by the applicants now US. Pat. No, 3,621,706.

Liquids with a wide variety of properties are used for heat transfer systems, fuel systems, hydraulic actuating systems, lubrication systems, etc. In many systems a safe and reliable operation depends on the liquids remaining in their liquid state and not changing to solids or to gases. Oxidation and low temperatures are common causes of liquids becoming solids while high temperature is a common cause for liquids changing into gases. The temperature at which a liquid begins to generate bubbles of vapor is called the boiling point.

Some liquids, like water, will turn completely into vapor if the initial boiling point temperature is maintained. Other liquids, such as some mineral oils, will require an increasing temperature to continue the boiling action. Liquids of this type are commonly checked for initial boiling point by a distillation method in which a heated flask and a horizontal condenser are utilized to drain condensed vapor into a graduate. The temperature of the liquid being heated in the flask when the first drop over occurs is called the initial boiling point. Liquids which are a mixture of several ingredients, such as hydraulic brake fluids, have been checked for boiling point by a reflux boiling point test also used for radiator coolants, antifreeze solutions, etc. This type of test establishes a stabilized temperature obtained when a condenser is returning a prescribed number of drops per second of condensed vapor to the hot fluid test sample. The existence of a small quantity of light end or low boiling point ingredients which vaporize at lower temperatures does not seriously impair the effectiveness of coolants. However, hydraulic brake systems cannot tolerate very much compressiblegas. Hydraulic brake fluid, as well as some fuels, have been found to vaporize under some conditions at temperatures below the reflux boiling point temperature because of lower boiling point fractions, chemical breakdown to produce more volatile fluids, and contamination by water, alcohol, etc. The percolating type of fluid vaporization tester disclosed in the above-mentioned application and also disclosed herein provides a simplified, fast operating, fluid vaporization indicator which will quickly and accurately perform the necessary testing on such liquids. A test sample is held in a boiler chamber which is heated by thermostatically controlled electric heaters. The test sample is connected to a visual indicator tube. As the test sample is heated, it will increase in volume by thermal expansion and this can be observed by the rise of the liquid level in the visual indicator tube. When the test sample begins to turn into vapor, the fluid column in the visual indicator tube will initially throb and the rate of rise in the tube will increase. When the fluid rises by a percolating action to the point of going over the loop of the tube the temperature at that time closely correlates with the temperature at which the fluid from which the test sample is taken will vaporize in actual use. A fan is utilized after the testing of the sample to cool the device and to provide a hot air blast for purging. By flowing the hot air which has absorbed heat from the boiler through the test chamber and the indicator tube the tested fluid sample is purged from the system so that no appreciable carry-over contamination is left to affect the test on the succeeding test sample. IN THE DRAWING:

FIG. 1 is a cross section view with parts broken away showing the mechanism embodying the invention.

FIG. 2 is a top view of the mechanism with the top cover removed.

The tester 10 has a base 12 to which is fastened a housing 14. The housing is divided] by a wall section 16 into a fan chamber 18 and a boiler chamber 20. An opening 22 through wall section 16 connects the lower parts of the two chambers. The upper end 24 of chamber 18 is connected with cooling air inlets 26 formed through a portion of housing 14. The upper end of chamber 20 is closed by the housing section 28. Both chambers are closed by the base 12 at their bottom ends. A fan 30 with its motor 32 is mounted in chamber 18 so that, when the motor is operating, outside air is moved from the air inlets 26 throughchamber 18 and opening 22 into the lower end of chamber 20.

Above the housing section 28 a cup 34 is mounted on a fill pipe 36 which extends through section 28 and connects with the boiler 38 mounted in chamber 20. A fill valve 40 in pipe 36 may be opened and closed at will by the person conducting the test. The boiler 38 includes two heating units 42 and a chamber 44 which receives the test sample. The lower end of the chamber is connected to a drain pipe 46 which extends through base 12 and terminates over a removable drain pan 48. A drain valve 50 is positioned in pipe 46, and it may also be opened and closed at will. Chamber 44 has a branch 52 extending upwardly and outwardly and connected to the indicator tube 54. This tube extends upwardly through housing section 28 and has a U-shaped bend 56 with the tube end 58 positioned over the cup 34.

Thermometer 60 extends through housing section 28 and into boiler 38 so that the temperature of the test sample can be determined and read. The cover 62 is provided to protect the portions of the tester above housing section 28 during storage and transport, as well as to guide the air during the purging operation. The cover is removed when tests are being run so that the appropriate observations may be made.

Aperture 64 in housing section 28 is positioned so that the cover plate 66 may be pivotably positioned to open and close the aperture as desired. When cover 62 is in place and purging the system with hot air, aperture 64 connects chamber 20 and the interior of cover 62.

The mechanism is provided with a suitable control switch 68 which controls the heating units 42 and the fan 32. Heating unit indicators 70 and 72, also mounted on the base, may be provided as lights which indicate the amount of energy being transmitted to the heaters. A suitable electrical power supply line 74 is connected through the control switch 68 to the fan motor and the heating units.

In order to initiate a test, the cover 62 is removed, fill valve 40 and drain valve 50 are closed, and the fluid test sample is placed in cup 34. Fill valve 40 is then opened, allowing the fluid to move through pipe 36 and into Chamber 44 and part of its branch 52. Fill valve 40 is then closed and control switch 68 is actuated so as to energize the heating units 42. This causes the test sample in the boiler to be heated.

As the fluid is heated it increases in volume. This can be observed as the fluid level rises in the tube 54. One of the heating units may have been set to be shut off by its thermostat at about 175 F. if hydraulic brake fluid is being tested, for example. A thermostat adjustment may be provided so that this cut-off point may be changed as desired. A second thermostat controls the other heating unit and the maximum temperature. The second heater thermostat is preferably set to de-energize the second heater at a limit such as 500 F, when hydraulic brake fluid is being tested, or at such other desirable limit which will give a sufficient testing range and not exceed the thermometer limit. The thermostat controlling the second heater may be set to hold the boiler temperature at any desired temperature. If, for example, it is set at the minimum vaporization temperature which is permitted, and no fluid is percolating over the loop 56 when this temperature is reached, the test sample has met the minimum vaporization temperature specification.

When the test mechanism is being operated to determine the vaporization point, it has been heated quickly by both heating elements until one has been cut off by its thermostat, and then more slowly by the remaining heating element. As the test fluid sample begins to vaporize, the initial throbbing action of the fluid in the indicator tube 54 will occur, the fluid will rise rapidly in the tube, and will be observed to go over the loop 56 and drop into the fill cup 34. The temperature registered by thermometer 60 at this time is observed and recorded as the vaporization temperature for that test sample.

The heating units are turned off immediately after the percolating action occurs indicating that vaporization temperature has been reached. The shutter 76, in the side of chamber 20 and controlling the air outlet, is then closed. The cover plate 66 is moved to open the hot air blast aperture 64, the cover 62 is installed, valves 40 and 50 are opened, and the fan motor 32 is turned on. The test sample flows downwardly into the drain pan 48, air is moved by fan 30 through opening 22 and into chamber 20. As the air passes over boiler 38 to cool the boiler, the air is heated. The hot air passes through aperture 64 and into the cover 62. As illustrated by the dashed arrows, air passing through tube 54 to branch 52 of the boiler chamber 44 also passes through fill cup 34, pipe 36, open valve 40 and the boiler chamber 44. The air passes outwardly through pipe 46 and open valve 50. It is desirable to allow the fluid and vapor being purged by the hot air to flow into the drain pan until the temperature registers a temperature of about 150 F. At this point the valves 40 and 50 may be closed, the shutter 76 open, the cover 62 removed, and the cover plate 66 moved to close aperture 64. The fan may be turned off when the temperature reaches about F. This purging operation should be followed if the test mechanism has not been recently used, or if a test has just been completed.

A fluid vaporization testing mechanism has been provided which permits a quick and thorough purging of the device to remove a tested sample before a new test sample is inserted. The entire operation can be accomplished in 3 or 4 minutes as compared to test operations of much larger duration when the reflux or distillation methods are used. The mechanism is sufficiently accurate to be utilized to spot check fluids on a production line basis shortly before they are inserted in an automobile, for example. It is also capable of being used effectively by service centers and vehicle inspect-ion stations.

What is claimed is:

1. In a fluid vaporization tester having a housing defining a boiler chamber with a boiler including heating means for heating test fluid, a testing tube leading upwardly from said boiler and reverse-bent to extend downwardly to a boiler fill cup, valve and conduit means selectively connecting the cup with said boiler, drain means for selectively draining test fluid from said boiler, and a cover for the boiler fill cup and reversebent portion of the testing tube and when in place defining a second chamber adjacent said boiler chamber, the improvement comprising:

means for forcing cooling air into said boiler chamber,

first air valve means selectively opened and closed and positioned in said housing for venting said boiler chamber to atmosphere after air has passed around said boiler for cooling,

and second selectively opened and closed air valve means positioned in said housing fluidly intermediate said boiler chamber and said second chamber and when open with said first air valve means closed and said cover in place venting said boiler chamber through said second chamber and said testing tube and said boiler and said drain means to purge said testing tube and said boiler of test fluid after testing has been completed.

2. In a vaporization testing mechanism for measuring the vaporization temperature of a liquid sample by heating it in a boiler and measuring the temperature of the liquid at a predetermined condition, hot air purge means comprising:

a fan for forcing air over the boiler to cool the boiler and heat the air, and passage means directing the hot air through the boiler to purge the boiler of liquid which has been tested.

3. The method of testing a series of liquid samples for vaporization and purging the mechanism of tested liquid between each test, comprising the steps of:

a. heating the sample liquid to vaporize a portion thereof,

b. percolating a portion of the sample liquid through a visible inverted U-shaped indicator by gas pressure of the vaporized liquid,

0. measuring the temperature of the sample liquid at the time of the first percolating surge of sample liquid through and beyond the highest point of the visible inverted U-shaped indicator,

d. cooling the sample liquid heater by air and thereby heating the air,

e. and directing the air so heated through the liquid heater and the indicator to purge them of tested liquid. 

1. In a fluid vaporization tester having a housing defining a boiler chamber with a boiler including heating means for heating test fluid, a testing tube leading upwardly from said boiler and reverse-bent to extend downwardly to a boiler fill cup, valve and conduit means selectively connecting the cup with said boiler, drain means for selectively draining test fluid from said boiler, and a cover for the boiler fill cup and reverse-bent portion of the testing tube and when in place defining a second chamber adjacent said boiler chamber, the improvement comprising: means for forcing cooling air into said boiler chamber, first air valve means selectively opened and closed and positioned in said housing for venting said boiler chamber to atmosphere after air has passed around said boiler for cooling, and second selectively opened and closed air valve means positioned in said housing fluidly intermediate said boiler chamber and said second chamber and when open with said first air valve means closed and said cover in place venting said boiler chamber through said second chamber and said testing tube and said boiler and said drain means to purge said testing tube and said boiler of test fluid after testing has been completed.
 2. In a vaporization testing mechanism for measuring the vaporization temperature of a liquid sample by heating it in a boiler and measuring the temperature of the liquid at a predetermined condition, hot air purge means comprising: a fan for forcing air over the boiler to cool the boiler and heat the air, and passage means directing the hot air through the boiler to purge the boiler of liquid which has been tested.
 3. The method of testing a series of liquid samples for vaporization and purging the mechanism of tested liquid between each test, comprising the steps of: a. heating the sample liquid to vaporize a portion thereof, b. percolating a portion of the sample liquid through a visible inverted U-shaped indicator by gas pressure of the vaporized liquid, c. measuring the temperature of the sample liquid at the time of the first percolating surge of sample liquid through and beyond the highest point of the visible inverted U-shaped indicator, d. cooling the sample liquid heater by air and thereby heating the air, e. and directing the air so heated through the liquid heater and the indicator to purge them of tested liquid. 